The identification LEDs of the adapters supported by the

.Nm

driver can be controlled via the

.Xr led 4

API for localization purposes.

.Sh LOADER TUNABLES

Tunables can be set at the

.Xr loader 8

prompt before booting the kernel or stored in

.Xr loader.conf 5 .

.Bl -tag -width indent

.It Va hw.em.disable_crc_stripping

Disable or enable hardware stripping of CRC field.

This is mostly useful on BMC/IPMI shared interfaces where stripping the CRC

causes remote access over IPMI to fail.

Default 0 (enabled).

.It Va hw.em.eee_setting

Disable or enable Energy Efficient Ethernet.

Default 1 (disabled).

.It Va hw.em.msix

Enable or disable MSI-X style interrupts.

Default 1 (enabled).

.It Va hw.em.smart_pwr_down

Enable or disable smart power down features on newer adapters.

Default 0 (disabled).

.It Va hw.em.sbp

Show bad packets when in promiscuous mode.

Default 0 (off).

.It Va hw.em.rxd

Number of receive descriptors allocated by the driver.

The default value is 1024 for adapters newer than 82547,

and 256 for older ones.

The 82542 and 82543-based adapters can handle up to 256 descriptors,

while others can have up to 4096.

.It Va hw.em.txd

Number of transmit descriptors allocated by the driver.

The default value is 1024 for adapters newer than 82547,

and 256 for older ones.

The 82542 and 82543-based adapters can handle up to 256 descriptors,

while others can have up to 4096.

.It Va hw.em.rx_int_delay

This value delays the generation of receive interrupts in units of

1.024 microseconds.

The default value is 0, since adapters may hang with this feature

being enabled.

.It Va hw.em.rx_abs_int_delay

If

.Va hw.em.rx_int_delay

is non-zero, this tunable limits the maximum delay in which a receive

interrupt is generated.

.It Va hw.em.tx_int_delay

This value delays the generation of transmit interrupts in units of

1.024 microseconds.

The default value is 64.

.It Va hw.em.tx_abs_int_delay

If

.Va hw.em.tx_int_delay

is non-zero, this tunable limits the maximum delay in which a transmit

interrupt is generated.

.El

.Sh FILES

.Bl -tag -width /dev/led/em*

.It Pa /dev/led/em*

identification LED device nodes

.El

.Sh EXAMPLES

Make the identification LED of em0 blink:

.Pp

.Dl "echo f2 > /dev/led/em0"

.Pp

Turn the identification LED of em0 off again:

.Pp

.Dl "echo 0 > /dev/led/em0"

.Xr led 4 ,